As police departments across the country increasingly come under federal pressure amid accusations of racially biased practices, law firms are vying for the job of enforcing the U.S. Department of Justice's prescription for change.

But those roles, which entail garnering respect from the public, local politicians and the police departments in question, are often highly scrutinized and are not necessarily all that lucrative when it comes to sought-after client engagements.

Squire Patton Boggs was the latest firm to step in the fray when government investigations and white-collar partner Clark Ervin was appointed an independent monitor of the Ferguson Police Department on Monday. Ervin acknowledged that the monitorship in Ferguson, Missouri, may face particular scrutiny given the iconic role that the northern St. Louis suburb now plays in the public's consciousness.

"It's a huge job, there's no question about that," Ervin said. "We regard this monitorship as particularly important and we regard it as a form of public service."

Ervin and his Squire Patton team have agreed to a $1.25 million cap on expenses over five years and no more than $350,000 for any single year, which will be paid by the city of Ferguson. But like other independent monitors, Ervin said the group is prepared to put in substantially more time and energy than they will be billing for as a result of the high-profile assignment.

Ferguson is one of nearly 30 police departments that have faced Justice Department intervention since the passage of the Violent Crime Control and Law Enforcement Act of 1994. Police departments in Cincinnati, Los Angeles and Pittsburgh were the subject of consent decrees mandating reforms under the Clinton administration, before the practice petered out when George W. Bush became president.

But the Justice Department's special litigation section, which handles such matters, has been busy under the Obama administration, issuing consent decrees in Cleveland, New Orleans and Cleveland, among other cities. Law firms, nonprofits and consultancies have entered fierce competitions to take on the high-profile task of evaluating a police department's progress and reporting on it to the public and federal courts, despite the relatively low rates they can charge for their services.

A team led by Sheppard, Mullin, Richter & Hampton partner Jonathan Aronie hired to monitor the New Orleans Police Department agreed to a five-year cap of $8.5 million and charges between $350 and $425 per hour—prices the firm said in its application were "significantly below our standard commercial rates."

Cleveland's monitor, Matthew Barge, a former associate at Skadden, Arps, Slate, Meagher & Flomwho now serves as vice president and deputy director of the Police Assessment Resource Center, said his team is billing about half of its time pro bono. Barge's group has also agreed to a $4.95 million cap for its services over five years.

Still, in New Orleans, the monitor has been accused of lagging in efficiency because they are "being handsomely rewarded" and a city councilman in Cleveland questioned whether Barge was actually working on all the days he has billed.

Samuel Walker, a professor emeritus of criminal justice at the University of Nebraska at Omaha who has studied police accountability, said he has no sympathy for cities that complain about the costs of a consent decree.

"Much of what they're paying for are things they should have done years before," Walker said. "What is the social and human cost of allowing people to police unconstitutionally? People are beaten up … it affects the whole community."

Ervin's team has a comparatively small budget in Ferguson, though Walker said the city's police department is not nearly the size of that in Cleveland or New Orleans.

"It is lower than most and that is challenging," Ervin said, but added that his team is "committed to do whatever's required to get the job done."